AMD CPU AMD Sempron S754 2800+ 256Kb BOX SDA(C)2800BABOX User Manual

31993A-1 September 2004

Thermal limits in motherboard design are necessary to protect 
the processor from thermal damage. T

S H U T D OW N  

is the 

temperature for thermal protection circuitry to initiate 
shutdown of the processor. T

SD_DELAY 

is the maximum time 

allowed from the detection of the over-temperature condition to 
processor shutdown to  preve nt   t h erm al   d a mag e  to  t he  
processor. 

Systems that do not implement thermal protection circuitry or 
that do not react within the time specified by T

SD_DELAY

 can 

cause thermal damage to the processor during the unlikely 
events of fan failure or powering up the processor without a 
heat-sink. The processor relies on thermal circuitry on the 
motherboard to turn off the regulated core voltage to the 
processor in response to a thermal shutdown event. 

Thermal protection circuitry reference designs and thermal 
solution guidelines are found in the following documents: 

■

AMD Athlon™ Processor-Based Motherboard Design Guide, 
order# 24363 

■

AMD Thermal, Mechanical, and Chassis Cooling Design Guide, 
order# 23794

See http://www.amd.com for more information about thermal 
solutions.

Table 14 shows the T

SHUTDOWN 

and T

SD_DELAY 

specifications 

for circuitry in motherboard design necessary for thermal 
protection of the processor.

 

T

SHUTDOWN

Thermal diode shutdown temperature for processor protection

125

°C

1, 2, 3

T

SD_DELAY

Maximum allowed time from T

SHUTDOWN

 detection to processor shutdown

500

ms

1, 3

processor relies on thermal circuitry on the motherboard to turn off the regulated core voltage to the processor in response to a 
thermal shutdown event. Refer to AMD Athlon™ Processor-Based Motherboard Design Guide, order# 24363, for thermal 
protection circuitry designs.